1. Field of the Invention
The present invention relates to a device for displaying or indicating an imagery three-dimensionally, so that the indicated imagery is viewed in the eyes of a person looking thereat as if it was a three-dimensional imagery.
2. Description of Prior Art
Many researches and developments have been made to produce an effective display device for displaying a three-dimensional imagery, with a plenty of various three-dimensional display devices having been made available on the market. Among them, there has been known a spherical three-dimensional display device which optically projects an imagery (or image) to a spherical screen to thereby display an imagery three-dimensionally on a spherical surface of the screen. This kind of spherical three-dimensional display device is frequently used for visual simulation of earth or natural environmental changes and symptoms. Typical examples thereof are “Gaia Vision” and “Geo Cosmos”, which are each well known in Japan as a name of spherical three-dimensional display device. The “Gaia Vision” display device is found in the Japanese public facility “Center For Environmental Science in Saitama” (i.e. “Saitama-Ken Kankyou Kagaku Kokusai Center” in Japanese) located in Saitama-ken, Japan, whereas the “Geo Cosmos” display device is found in the Japanese public facility “National Museum of Emerging Science and Innovation” (i.e. “Nihon Kagaku Mirai Kan” in Japanese) located in Tokyo, Japan.
Naturally, in those public facilities, a capability for indicating precise image information is required in the spherical three-dimensional display device to meet specific requirements specialized in this technical filed. For that reason, it is necessary to provide various precision electronic and mechanical elements in order to form an optimal display device of this kind, wherein the precision electronic and mechanical parts include a precisely formed dome screen, a video projector with fish-eye lens specifically designed and produced for projecting an imagery to a spherical surface, an extraordinary large number of LED indicators, complicated system programs, and so forth. Further, installation of those constituent elements to provide a desired mode of display device requires an extremely high precision in determining positions and angles of the associated elements with one another, and also requires maintenance for each of the elements.
Consequently, while featuring the three-dimensional vision in contrast to two-dimensional vision, a multimillion or billion amount of expenses, or a multibillion amount of expenses depending on the kind of required equipments, have been incurred for installing the foregoing spherical three-dimensional display device. This has raised a serious problem in equipment expenses and costs.
In addition, in order to indicate a precise imagery or image on the entire spherical surface of dome screen of the spherical display device, it is necessary to effect complete corrections for aberration, and therefore, it is essential to provide a video projector with a fish-eye lens having a curvature equal to that of the dome screen and to precisely install that video projector at a given position and at a given angle with respect to the dome screen. Apparently, a high technical expertise and precision work have been required for that purpose, thus unfavorably raising an extreme difficulty in design and production of the video projector.
In place of such video projector arrangement, it may be proposed to assemble a great number of special LED indicator plates together into a dome configuration so as to provide a desired spherical display device. But, in such case, it is necessary to design and custom-build each of the special LED indicator plates, and further, in assembly, workers must carefully put together those LED indicator plates with precision into a desired dome shape, which results in an unexpected high increase of costs involved.
In view of the foregoing circumstances, the hitherto spherical three-dimensional display devices have encountered the problem that they require quite a lot of specially designed parts and equipments as well as high costs, thereby making it difficult to reduce them to a widespread practice in general. Moreover, most of the conventional spherical three-dimensional display devices have been mainly used for displaying a spherical image of the earth and effecting an imaginary simulation of cloud flow over the earth, and therefore, none of the spherical display devices has been developed for other uses than those geographical and geoscientific purposes.